The present invention relates to a hydraulic device for one of a motor or pump, and, more particularly, to a gerotor device with a manifold assembly positioned between a gerotor set and a housing for the device, wherein fluid is routed from one of the gerotor set and the housing through an internal bore in the manifold assembly, radially and axially through the manifold assembly to the other of the gerotor set and the housing.
The use of rotary fluid pressure devices for motors and pumps is well known in the art. One type of rotary fluid pressure devices is generally referred to as gerotors, gerotor type motors, and gerotor type pumps, hereinafter referred to as gerotor motors. Gerotor motors are compact in size, low in manufacturing cost, have a high-torque capacity ideally suited for such applications as turf equipment, agriculture and forestry machinery, mining and construction equipment, as well as winches, etc.
Typically these devices are comprised of several aligned components for routing fluid for the purpose of supplying a driving force. These components typically include a manifold assembly, which is generally positioned between a gerotor set and a housing for the device. The gerotor sets utilize a special form of internal gear transmission consisting of two main elements: an inner rotor and an outer stator. The manifold assembly directs pressurized fluid to the gerotor set and exhaust fluid from the gerotor set. The manifold assembly has a central internal bore which receives a drive link (for a wobble type device) or a through shaft.
Gerotor motors can be classified as having either a two-pressure zone (high-pressure and low-pressure) or a three-pressure zone (high-pressure, low-pressure, and case-pressure). Currently, multi-plate manifolds are used on three-pressure zone motors with low speed valving devices. For a three-pressure-zone motor, the central cavity of the motor is filled with fluid of case drain pressure and cannot be used as a fluid passageway. In these designs, fluid passageways in the manifold assembly are separate from the central cavity of the motor. If the fluid passageway were to be connected with the central cavity of the motor, cross-port leakage would take place. The present invention provides a two-zone motor which utilizes the central cavity of the motor as a fluid passageway to either supply or receive hydraulic fluid to or from the manifold assembly. The manifold assembly includes radial pathways which directly connect with the central cavity of the motor.
Other prior art two-zone motor designs provide a separate component, adjacent to the manifold assembly, which fluidly connects the manifold assembly with the central cavity of the motor. A separate component is needed since the manifold assembly does not directly have a passageway radially connected with the central cavity. The present invention eliminates the need for this separate component by providing passageways in the manifold assembly that directly connect with the central cavity. The overall length of the motor is reduced by eliminating this component. The elimination further reduces the possibility of cross-port leakage between the manifold assembly and the added component.
A feature of the present invention is to provide a hydraulic device for one of a motor and pump, having a manifold assembly positioned between a gerotor set and a housing for the device, being adapted for conducting pressurized fluid to the gerotor set and conducting exhaust fluid from the gerotor set. The manifold assembly including a first axial end, a second axial end, a central internal bore extending freely from the first axial end to the second axial end and being adapted for conducting at least a portion of one of the fluids. A first fluid passage extends directly from the central internal bore to a location radially outward from the central internal bore and therefrom to the second axial end. A second fluid passage extends substantially laterally from the second axial end to the first axial end.
In the noted hydraulic device, the central internal bore can include openings through both of the axial ends. Additionally the central internal bore can receive one end of a torque-transfer shaft for connecting to the gerotor set. Also, the manifold in the noted hydraulic device can include an intermediate portion located between the axial ends having a central aperture including a plurality of circumferentially spaced outwardly generally radially directed openings in communication therewith. Further, this central aperture can be greater in diameter than the diameter of the central internal bore axial end openings. Also the intermediate portion central aperture and its outwardly generally radially directed openings can form a portion of the first fluid passage.
Also in the noted hydraulic device the manifold assembly intermediate portion can have a series of comb-like openings, each of the openings having a plurality of circumferentially spaced, inwardly directed substantially radial tooth-like members. Further these radial tooth-like members can form a portion of the second fluid passage. Also further, the tooth-like members can extend between but are spaced from the outwardly radially directed openings.
Also in the noted hydraulic device, the manifold assembly can include a series of individual axially arranged plates affixed to each other. Further in the noted hydraulic device, the manifold first axial end is adjacent to and fluidly connected with the housing and the manifold second axial end is adjacent to and fluidly connected with the gerotor set.
Additionally in the noted hydraulic device, the first fluid passage can be filled with high pressurized fluid and the second fluid passage can be filled with exhaust fluid. Furthermore, the first fluid passage can be filled with exhaust fluid and the second fluid passage can be filled with high pressurized fluid.
Further in the noted hydraulic device, the manifold assembly can provide a fluid valving interface in conjunction with an adjacent surface of the gerotor set.
A further feature of the present invention includes having a manifold assembly for use in a hydraulic device comprised of a series of centrally apertured individual plates sealingly affixed to each other and having a common central axial through bore. Each of the plates having a respective first portion of a first passage and a respective second portion of a second passage extending therethrough. The affixed plates together define axially spaced first and second axial end surfaces and a first and second fluid path comprised of the respective first and second passages. The first path extends laterally from the second axial end surface through the plate into an intermediate one of the plate via the central axial bore, and then substantially radially outwardly from the central bore, within the intermediate plate and substantially laterally from the intermediate plate and substantially laterally through an adjacent one of the plate, to the first axial end surface. The second fluid path extends initially from the second axial end surface in a substantially axial direction through the plate followed by initially extending substantially axially laterally, subsequently substantially radially outwardly and thereafter substantially laterally from the intermediate plate without contact with the central bore, and finally extending substantially laterally through the adjacent one of the plates, so as to terminate at the first axial surface.
Additionally in this noted manifold assembly, the intermediate plates include a generally cylindrical central aperture including a plurality of circumnferentially spaced outwardly radiating openings extending therefrom and in communication with the central bore.